The edible battery is certainly not a delicacy. But it can be broken down completely safely in the body. The team around Mario Caironi from Italian Institute of Technology in Genoa wants his chocolate-sized battery as a power source for also biodegradable sensors that can measure health parameters in the body. This work is still in its infancy, but Caironi does not rule out that his approach could also lead to larger, more powerful batteries without pollutants.
In their search for a suitable recipe for the edible battery, the researchers were inspired by natural, biochemical redox reactions. So they chose vitamin B2 (riboflavin) as the cathode material for their battery. The anode consists of the yellow natural dye quercetin, which is also found in capers and chives. The liquid electrolyte is water based enriched with activated charcoal to increase electrical conductivity. Edible nori algae, also used to prepare sushi, act as a separator between the half-cells of the battery. Sealed with beeswax, the scientists added thin strands of gold for the electrical connection.
Amperage of the edible battery
However, a first prototype of the battery does not supply much electricity. At a voltage of 0.65 volts, it achieves a current of 48 microamps for twelve minutes. As low as these values are, they are sufficient for the supply of individual light-emitting diodes and small sensors. After five charge cycles, the capacity even increased to 7.2 milliampere hours per gram, but dropped to 54 mAh/g after 50 charge cycles.
“The potential of these edible batteries lies in powering sensors that measure health parameters in humans or the storage conditions of food,” says Caironi. In addition, he can imagine using it in safe children’s toys or edible robotics. “We are currently developing batteries with a larger storage capacity and smaller dimensions,” says the developer.
And perhaps this research into edible electronics will also lead to new battery concepts that, for example, do not require fluorine-containing materials – PFAS for short. Because currently no lithium-ion battery can do without fluoropolymers, the ban of which is currently being discussed at European level.
(jl)
